Hydrochloric acid is employed in many technological fields, where its delivery to the place of use may sometimes cause considerable problems.
This is particularly true if the place of use is located in regions of use that are difficult to reach. Thus, for example, hydrochloric acid may be employed on a large scale in sea water desalination plants as an anti-scaling and cleaning agent.
Hydrochloric acid is moreover employed in oil drilling in order to open up pores in a rock formation and produce carbon dioxide in the carbonate rock in order to enhance the conveying efficiency.
In addition, hydrochloric acid is also employed in remote regions as a cleaning and disinfecting agent or a mordant.
Particularly for the case that the place of use is located in a region that may only be reached with difficulty, such as remote parts of the country or islands, concentrated hydrochloric acid is employed for the purposes named in the foregoing. The use of concentrated acid on the one hand has the advantage that the bulk having to be transported may be kept small.
On the other hand, however, there is a permanent risk of the respective transport containers developing a leak. Moreover, during the transport of concentrated, fuming hydrochloric acid, volatile HCl gas is generally also emitted to the environment. This may result in corrosion occurring in the vicinity of the transport vessels.
As an alternative, the use of technical sulfuric acid is also frequently preferred. The latter is concentrated in a substantially higher degree and presents a normality concentration in val/L that is about three times as high.
Thus, despite the oftentimes better suitability of hydrochloric acid for a predetermined process, it is preferred to employ the non-fuming sulfuric acid which has no impact on the vicinity and is less corrosive. On the other hand, sulfuric acid forms poorly soluble salts with the alkaline earth metal ions Ca2+, Sr2+, and Ba2+. This may possibly result in undesirable precipitations.
For technological reasons as well as in consideration of the safety aspects set forth in the foregoing, the use of diluted hydrochloric acid would therefore also be desirable in regions of use that are difficult to reach such as, e.g., sea water-desalination plants or oil drilling platforms.